Glaucoma and Aging
Chat Highlights
May 25, 2005

On Wednesday, May 25, 2005, Dr. Jeff Henderer a glaucoma specialist at Wills, and the glaucoma chat group discussed "Glaucoma and Aging."

Moderator:  Welcome back to chat Dr. Henderer. Tonight our topic is "Glaucoma and Aging."  Shall we start at the beginning of the aging process? Is the eye fully developed at birth?

Dr. Jeff Henderer:  Actually, no. The eye is anatomically formed, but functionally it does not work at full capacity until about six months.  Believe it or not, you have to train your brain to see.

P:  Does the eye change in childhood and the teen years?

Dr. Jeff Henderer:  The eye is pretty much formed at about age 6 or 7.  That's about the time the eye-brain connections are fixed.  After that, not much changes. The eye, however, can change, grow and become near-sighted.

P:  In adulthood, what changes in the eye?

Dr. Jeff Henderer:  Adulthood is a time of stability.  Not much really changes until cataracts form after about age 40 or so.  Until then, the eye can "flex" the lens to permit close reading, but after that the lens loses this ability, so we need reading glasses. [Editor's note: That change is called presbyopia.]

Moderator:  How does the eye flex?

Dr. Jeff Henderer:  The lens can change its shape to bend the light more powerfully, thereby allowing you to focus on close objects.

P:  Is there one kind of glaucoma that is more prevalent as we age?

Dr. Jeff Henderer:  Open-angle glaucoma is far and away the most common form of glaucoma in the U.S.  That disease is more prevalent as we age.  We don't know why that is.

Moderator:  Is that true in other nations?

Dr. Jeff Henderer:  In Japan, there is some evidence that normal-tension glaucoma might be the more common form.  In some Asian countries, there is a great deal of angle-closure glaucoma, which is more common with age.

P:  Does a glaucomatous eye age differently than a non-glaucomatous eye?

Dr. Jeff Henderer:  I don't think there is really much difference between eyes with and without glaucoma in terms of onset of having to use reading glasses and such.  But treating glaucoma can accelerate the growth of cataract.

Moderator:  Do you treat an elderly patient different than you treat a young adult?

Dr. Jeff Henderer:  Sure. For the most part, I am more concerned about the young patient.

P:  It's understandable that as a doctor you'd be more concerned with younger patients, as sight must be preserved for a longer time.  What percentage of your patients is under age 55?

Dr. Jeff Henderer:  Fortunately. that demographic does not often get glaucoma.  I'd say that only about 15% of my patients are in that age range.

P:  I think it is odd that I can still read, see people, etc., close-up without glasses, and yet I've had glaucoma for more than 25 years. Most of the people my age that I know can't read without glasses.  Yet my doctor says my glaucoma is advanced and my optic nerve has substantial damage. Does that seem unusual?

Dr. Jeff Henderer:  It is not unusual. Fortunately for us, the optic nerve holds on to central vision until the bitter end. That means people can often see quite well.  But it may be tunnel vision. It sounds as if you might be nearsighted.

P:  Does IOP (intraocular pressure) increase with age? Does the trabecular meshwork tend to "wear out" or get clogged over time (aside from pseudoexfoliation or pigment dispersion syndromes)?

Dr. Jeff Henderer:  No one knows exactly why the IOP generally increases with age.  It must be the trabecular meshwork. I'm not sure that anyone knows exactly why this occurs.  In the types of glaucoma you mentioned, a mechanical obstruction is present.

P:  Is surgery recommended more often for young and middle-aged people than for old folks?

Dr. Jeff Henderer:  That depends more upon on how the treatments are working, how much glaucoma is present, and the general health of the patient.

P:  How much of an increase in IOP can be expected with, say, each ten additional years of life?

Dr. Jeff Henderer:  Not much in terms of absolute numbers.  Perhaps only a point or so.  But that is a statistical change.

P:  If a patient has scarring from angle-closure attacks, will more of the angle scar over time?

Dr. Jeff Henderer:  That is one of the principal ways that angle closure leads to trouble, even after the attack. The same could be said for recurrent bouts of inflammation.

P:  Should pigment dispersion be expected to abate with the onset of presbyopia?  I've just gotten to the point (at age 54) where my near vision is very bad.  I hope that a positive side to that might be a lessening of contact between the iris and zonules via age-related changes in the shape of the lens.  Are there other factors that accompany old age that also result in a decrease in pigment release?  Can you explain how that works?

Dr. Jeff Henderer:  You are correct that the amount of dispersion generally decreases at about your age, because there is less lens-iris rubbing.  You actually have summarized it quite nicely.

P:  Is open-angle glaucoma a progressive disease?  That is, does it still progress even with medication or surgery, or will these interventions halt the progression?

Dr. Jeff Henderer:  We believe that for most optic nerves there is a "threshold IOP."  That means that if we lower the IOP enough, we will be able to slow or, we hope, prevent deterioration.  The problem is that we don't know what that threshold is until we treat and watch to see the effects.

P:  My father has been diagnosed with what's probably primary open-angle glaucoma associated with a plateau configuration iris base and end-stage glaucomatous optic neuropathy.  Can you translate that for me?

Dr. Jeff Henderer:  That is a bit complicated.  The open-angle part is the typical form of the disease in the US. The plateau part is an interesting sub-type of "narrow angles" and can be a cause of angle-closure glaucoma.  It's pretty uncommon. It may very likely be an associated finding and not really implicated in the glaucoma.

Moderator:  Thank you, Dr. Henderer. We look forward to your next visit.

On June 1, Dr. Wilson discussed "Chronic Illness Concerns" in the Chat room. Click here for highlights of that meeting.

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